Affibody PET Imaging of HER2-Expressing Cancers as a Key to Guide HER2-Targeted Therapy.

Human epidermal growth factor receptor 2 (HER2) is a major prognostic and predictive marker overexpressed in 15-20% of breast cancers. The diagnostic reference standard for selecting patients for HER2-targeted therapy is based on the analysis of tumor biopsies. Previously patients were defined as HER2-positive or -negative; however, with the approval of novel treatment options, specifically the antibody-drug conjugate trastuzumab deruxtecan, many breast cancer patients with tumors expressing low levels of HER2 have become eligible for HER2-targeted therapy.

Human Epidermal Growth Factor Receptor 2 (HER2) PET Imaging of HER2-Low Breast Cancer with [Ga]Ga-ABY-025: Results from a Pilot Study.

Patients with HER2-low metastatic breast cancer (mBC), defined as an immunohistochemistry (IHC) score of 1+ or 2+ without HER2 gene amplification, may benefit from HER2 antibody-drug conjugates. Identifying suitable candidates is a clinical challenge because of spatial and temporal heterogeneity in HER2 expression and discrepancies in pathologic reporting. We aimed to investigate the feasibility and safety of HER2-specific PET imaging with [Ga]Ga-ABY-025 for visualization of HER2-low mBC.

[ 18 F]-PSMA-1007 PET imaging optimization and inter-rater reliability - a comparison of three different reconstructions read by four radiologists.

Objectives: To increase understanding of optimal imaging parameters [ 18 F]PSMA-1007 when imaging patients with prostate cancer and to determine interrater agreement using [ 18 F]PSMA-1007.

Methods: In this observational study, four independent physicians read reconstruction sets using bedtimes of 1, 2 and 3 minutes of patients undergoing [ 18 F]PSMA-1007. positron emission topography.

Optimized, automated and cGMP-compliant synthesis of the HER2 targeting [Ga]Ga-ABY-025 tracer.

Background: The Affibody molecule, ABY-025, has demonstrated utility to detect human epidermal growth factor receptor 2 (HER2) in vivo, either radiolabelled with indium-111 (In) or gallium-68 (Ga). Using the latter, Ga, is preferred due to its use in positron emission tomography with superior resolution and quantifying capabilities in the clinical setting compared to In. For an ongoing phase II study (NCT05619016) evaluating ABY-025 for detecting HER2-low lesions and selection of patients for HER2-targeted treatment, the aim was to optimize an automated and cGMP-compliant radiosynthesis of [Ga]Ga-ABY-025.

Tumor Characterization by [Ga]FAPI-46 PET/CT Can Improve Treatment Selection for Pancreatic Cancer Patients: An Interim Analysis of a Prospective Clinical Trial.

Correct and timely diagnosis of pancreatic cancer (PC) is essential for treatment selection but is still clinically challenging. Standard-of-care imaging methods can sometimes not differentiate malignancies from inflammatory lesions or detect malignant transformation in premalignant lesions. This interim analysis of a prospective clinical trial aimed to evaluate the diagnostic accuracy of [Ga]fibroblast activation protein inhibitor (FAPI)-46 PET/CT for PC and determine the sample size needed to demonstrate whether this imaging technique improves the characterization of equivocal lesions detected by standard-of-care imaging methods.

[HER2-low breast cancer - A new entity that could expand possibilities of getting treatment].

Breast cancer is the most common form of cancer among women in Sweden. Several decades ago it was recognized that the Human epidermal growth factor receptor 2 (HER2) is involved in a critical growth system for breast cancer cells. Overexpression of HER2 (immunohistochemistry [IHC] 2+/3+, in situ hybridization [ISH] positive) is present in 15 percent of all breast cancers.

Multimodal perioperative assessment of liver function and volume in patients undergoing hepatectomy for colorectal liver metastasis: a comparison of the indocyanine green retention test, Tc mebrofenin hepatobiliary scintigraphy and gadoxetic acid enhanced MRI.

Objectives: To compare the dynamic changes in future liver remnant (FLR) function and volume after hepatectomy and to evaluate the associations between three modalities in assessment of liver function.

Methods: Liver function and volume were quantified pre-operatively, at post-operative day (POD) 7 and POD 28 in 10 patients with colorectal liver metastases undergoing hemihepatectomy using the indocyanine green retention (ICG) test, hepatobiliary scintigraphy (HBS) and gadoxetic acid-enhanced MRI. The Tc mebrofenin uptake rate in the FLR was applied as a reference of liver function.

Tc-Sestamibi SPECT/CT and histopathological features of oncocytic renal neoplasia.

Background: Tc-Sestamibi Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) contributes to the non-invasive differentiation of renal oncocytoma (RO) from renal cell carcinoma (RCC) by characterising renal tumours as Sestamibi positive or Sestamibi negative regarding their Tc-Sestamibi uptake compared to the non-tumoral renal parenchyma.

Purpose: To determine whether Tc- Sestamibi uptake in renal tumour and the non-tumoral renal parenchyma measured using Standard Uptake Value (SUV) SPECT, has a beneficial role in differentiating RO from RCC.

Material And Methods: Fifty-seven renal tumours from 52 patients were evaluated.

A 68Ga-FAPI-46 PET/CT Imaging Pitfall in Assessing Residual Gastric Cancer Early After Chemotherapy.

After neoadjuvant chemotherapy, preoperative imaging with 68Ga-FAPI-46 PET/CT showed a similar level of tracer uptake at the location of the primary tumors in 2 patients with gastric cancer. Postoperative histopathology revealed residual malignant cells only in one of the patients, whereas the elevated FAPI uptake in the other patient correlated to an inflammatory reaction and fibrosis. With this case, we would like to highlight that an increased FAPI uptake in inflammatory and fibrotic tissue early after chemotherapy may represent a potential interpretation pitfall.

99mTc-HMPAO-WBC SPECT/CT versus 18F-FDG-WBC PET/CT in chronic prosthetic joint infection: a pilot study.

Purpose: The aim of this study was to compare 99mTc-HMPAO-WBC-SPECT/CT combined with 99mTc-nanocollloid SPECT/CT and 18F-FDG-WBC-PET/CT combined with 99mTc-Nanocollloid SPECT/CT for the diagnosis and treatment evaluation of chronic prosthetic joint infection (PJI).

Methods: Patients with suspected chronic PJI were examined with 99mTc-HMPAO-WBC SPECT/CT, 18F-FDG-WBC PET/CT, and 99mTc-nanocolloid SPECT/CT (to visualize bone marrow). The location and patterns of uptake were noted and compared between the two leukocyte examinations.

Clinically Applicable Cyclotron-Produced Gallium-68 Gives High-Yield Radiolabeling of DOTA-Based Tracers.

By using solid targets in medical cyclotrons, it is possible to produce large amounts of GaCl. Purification of Ga from metal ion impurities is a critical step, as these metals compete with Ga in the complexation with different chelators, which negatively affects the radiolabeling yields. In this work, we significantly lowered the level of iron (Fe) impurities by adding ascorbate in the purification, and the resulting GaClcould be utilized for high-yield radiolabeling of clinically relevant DOTA-based tracers.

In Situ Metabolomics Expands the Spectrum of Renal Tumours Positive on Tc-sestamibi Single Photon Emission Computed Tomography/Computed Tomography Examination.

Background: Definite noninvasive characterisation of renal tumours positive on Tc-sestamibi single photon emission computed tomography/computed tomography (SPECT/CT) examination including renal oncocytomas (ROs), hybrid oncocytic chromophobe tumours (HOCTs), and chromophobe renal cell carcinoma (chRCC) is currently not feasible.

Objective: To investigate whether combined Tc-sestamibi SPECT/CT and in situ metabolomic profiling can accurately characterise renal tumours exhibiting Tc-sestamibi uptake.

Design Setting And Participants: A tissue microarray analysis of 33 tumour samples from 28 patients was used to investigate whether their in situ metabolomic status correlates with their features on Tc-sestamibi SPECT/CT examination.

Comparison of Regularized Reconstruction and Ordered Subset Expectation Maximization Reconstruction in the Diagnostics of Prostate Cancer Using Digital Time-of-Flight Ga-PSMA-11 PET/CT Imaging.

Unlabelled: In prostate cancer, the early detection of distant spread has been shown to be of importance. Prostate-specific membrane antigen (PSMA)-binding radionuclides in positron emission tomography (PET) is a promising method for precise disease staging. PET diagnostics depend on image reconstruction techniques, and ordered subset expectation maximization (OSEM) is the established standard.

Dual-tracer approach vs. dual time-point approach in leukocyte scintigraphy in treatment evaluation of persistent chronic prosthetic joint infection.

Background: Both dual time-point 99mTc-hexamethylpropylene amine oxime (HMPAO)-leukocyte scintigraphy and dual-tracer 99mTc-HMPAO-leukocyte scintigraphy (with the addition of 99mTc-nanocolloid bone marrow scintigraphy) have been used to diagnose prosthetic joint infection (PJI). A treatment evaluation of persistent PJI using these imaging protocols has yet to be presented.

Objective: The purpose of this study was to compare the accuracy of dual time-point 99mTc-HMPAO-leukocyte scintigraphy to the dual-tracer alternative of single time-point 99mTc-HMPAO-leukocyte scintigraphy or single-photon emission computed tomography/computed tomography (SPECT/CT) combined with a 99mTc-nanocolloid bone marrow scintigraphy or SPECT/CT, for treatment evaluation of PJI.

Combining contrast-enhanced ultrasound, CT perfusion and Tc-Sestamibi SPECT/CT to guide diagnosis in a case of solid renal tumour.

Definitive, pre-operative differentiation of solid renal lesions by ultrasound, contrast-enhanced multiphasic CT or MRI examinations is often not possible. An increasing amount of literature indicates the added value of Tc-Sestamibi SPECT/CT, CT perfusion and contrast-enhanced ultrasound in the pre-operative characterisation of solid renal tumours. This case report presents the diagnostic approach of a solid renal tumour that turned out to be a hybrid oncocytic chromophobe tumour in a patient with Stage 3 renal failure by combining the three aforementioned modern examination techniques.

Preoperative detection of sentinel lymph nodes with hybrid SPECT/computed tomography imaging may improve the accuracy of sentinel lymph node biopsies in patients with early stages of cancer of the oesophagus or gastro-oesophageal junction.

Objectives: The aim of this study was to investigate the sentinel lymph node biopsy (SLNB) method in patients with cancer of the oesophagus or gastro-oesophageal junction (GOJ) guided by preoperative hybrid single-photon emission tomography/computed tomography (SPECT/CT) lymphoscintigraphy.

Methods: Thirty-nine patients with stage T1-T3, any N-stage, M0 cancer of the oesophagus or GOJ planned for curatively intended esophagectomy underwent preoperative SPECT/CT lymphoscintigraphy following endoscopically guided submucosal injection of radiocolloid and intraoperative radio-guided SLNB using a hand-held gamma scintillation device.

Results: The detection rate in preoperative SPECT/CT imaging was 88%.

Antenatally detected urinary tract dilatation: a 12-15-year follow-up.

Background: Antenatally diagnosed urinary tract dilatation (UTD) still burdens healthcare providers and parents. This study was conducted to establish long-term outcome in an unselected group of children with antenatally detected UTD.

Methods: Seventy-one out of 103 children born in 2003-2005 and diagnosed with antenatal UTD agreed to participate in a 12-15-year follow-up including blood and urine samples, a kidney ultrasound exam, and kidney scintigraphy.

Hepatobiliary scintigraphy and kinetic growth rate predict liver failure after ALPPS: a multi-institutional study.

Background: Post hepatectomy liver failure (PHLF) after ALPPS has been related to the discrepancy between liver volume and function. Pre-operative hepatobiliary scintigraphy (HBS) can predict post-operative liver function and guide when it is safe to proceed with major hepatectomy. Aim of this study was to evaluate the role of HBS in predicting PHLF after ALPPS, defining a safe cut-off.

Comparison of acquisition protocols for ventilation/perfusion SPECT-a Monte Carlo study.

One of the most commonly used imaging techniques for diagnosing pulmonary embolism (PE) is ventilation/perfusion (V/P) scintigraphy. The aim of this study was to evaluate the performance of the currently used imaging protocols for V/P single photon emission computed tomography (V/P SPECT) at two nuclear medicine department sites and to investigate the effect of altering important protocol parameters. The Monte Carlo technique was used to simulate 4D digital phantoms with perfusion defects.

Comparison of lipiodol infusion and drug-eluting beads transarterial chemoembolization of hepatocellular carcinoma in a real-life setting.

Doxorubicin-eluting beads transarterial chemoembolization (DEB-TACE) is reported to improve survival and tolerability when compared with conventional lipiodol-TACE (cTACE) for the treatment of hepatocellular carcinoma (HCC). The aim of this study was to evaluate tolerability and long-term survival in patients treated with cTACE or DEB-TACE in a real-life setting. Incidence of adverse events and overall survival in HCC patients treated with either cTACE or DEB-TACE at Karolinska University Hospital 2004-2012 were analyzed retrospectively.

Is 99mTc-HMPAO-leukocyte imaging an accurate method in evaluating therapy result in prosthetic joint infection and diagnosing suspected chronic prosthetic joint infection?

Background: To investigate the sensitivity and specificity of 99mTc-HMPAO-leukocyte imaging in evaluating therapy result in patients with prosthetic joint infection (PJI) and in diagnosing suspected chronic PJI.

Methods: Sixty-two patients (63 joints) with microbiologically verified PJI were examined by leukocyte imaging to evaluate therapy result during or at the end of antibiotic treatment or if the patient had a chronic PJI after treatment. Group 1 consisted of 49 patients with on-going or within less than 14 days of ending antibiotic treatment examined to evaluate response.